The specific aim of this project is to investigate the etiology of Sjogern's Syndrome by establishing a central repository of these patients and determining if they differ with respect to Cytomegalovirus (CMV) expression or host immune responsiveness to CMV as compared to age-matched controls. The proposal that Sjogern's Syndrome is a late manifestation of latent CMV infection is based upon similar tissues of involvement, sexual dimorphism of the two entities and current theories of "autoimmunity". In essence, the CMV proteins expressed on the surface of glandular cells may act as the antigens necessary to initiate a misdirected immunologic attack. Salivary gland tissue and saliva will be tested for the presence of virus by cocultivation, viral antigens by immunoperoxidase and immunofluorescent staining and viral RNA by in-situ hybridization. Host serum and saliva will be analyzed by ELISA techniques for the presence of antibody specific for CMV while peripheral lymphocytes will be studied for blastogenic response following stimulation by CMV antigens. At the present time at our institution patients with Sjogern's Syndrome are evaluated and treated by a variety of departments including Oral Pathology, ENT, Opthalmology, Rheumatology and Connective Tissue Diseases. The proposed project would centralize these efforts as well as test a very plausable hypothesis linking CMV to the pathogenesis of Sjogern's Syndrome. If a positive association appears, evidence for a cause and effect relationship would be attempted in future animal studies as well as continued in prospective human studies.